普通车床的中心架多为如图1所示。用户反映的主要有3个问题: (1)支承工件的直径不够大(可调范围小); (2)工件压上后,顶丝2和螺母3因承受不了载荷而脱出; (3)当工件直径较大时,得转动螺杆4,使滑杆1向孔内缩回,但滑杆1上的螺孔与螺母3上的螺孔同轴度很难保证,1与3愈接近,螺杆4就 Ordinary lathe center frame as shown in Figure 1. (3) When the workpiece is pressed, the top wire 2 and the nut 3 can not be released because they can not bear the load. (3) When the diameter of the supporting workpiece is not big enough (the adjustable range is small) When the workpiece diameter is larger, the screw 4 may be rotated to retract the sliding rod 1 into the hole, but the coaxiality between the screw hole on the sliding rod 1 and the screw hole on the nut 3 is difficult to guarantee. The closer the 1 and 3 are, 4 right